Yes. You can file RTI to Assam Public Service Commission.
Assam Public Service Commission (APSC) was established in the year 1937 under the Government of India Act, 1935. After independence of India, the regulations of APSC came into force from September 1, 1951 and the Assam Public Service Commission (Limitation of Functions) Regulation was formally declared. Hence it comes under "Public Authority" under Section 2(h) of RTI Act 2005.
You can file RTI to know regarding recruitment details, seek question papers, see your own answer sheet or other related information recorded by the Commission.
For assistance of filing RTI please refer https://onlinerti.com/